Opinion: 9 things you should know about your privacy and rights in the digital age

Computerworld - Editor's Note: This article includes material from the book Blown to Bits: Your Life, Liberty, and Happiness After the Digital Explosion, publishing June 2008 by Addison-Wesley Professional. Authors are Harry Lewis, Ken Ledeen and Hal Abelson.

1. We know where you are.

If you have a cell phone, and a lot of people do, the phone company knows where you are. It has to. Otherwise it couldn't get any phone calls to you. Your cell phone reports its position fairly often to the cell towers in its area, and the phone company keeps that information around.

That's how the police were able to find Tanya Rider when she drove off the road. She didn't use her cell phone, but it was on and the police were able to find out where she was before her battery died.

2. Cars have black boxes, too.

Get in an accident, tell the state trooper that you were going 35 mph in a 40-mph zone, and he or she may tap into the black box in your car to see if you're lying. Many cars have them, and more will soon. These little devices record a host of facts about your driving: for example, how fast you were going and when you slammed on the brakes -- and recovering the data doesn't even require a search warrant.

3. Bits don't go away.

Remember that tasteless text message you sent last month? The phone company remembers it, too. After all, text messages are "just bits"; they don't take much space to store, so why not keep them forever, since you never know when someone will ask for them.

In June 2004, Kobe Bryant's attorneys gained access to the text messages of the woman who had accused him of raping her, including messages sent immediately after the encounter -- and including messages to her former boyfriend.

4. Your cell phone could be listening to you.

Your cell phone is a little radio station, capable of broadcasting and receiving, complete with a small computer that controls its functions. These computers can be programmed remotely -- no need to bring your cell phone into the store -- so that your phone will function as a roving bug, whether it is turned on or off. A court ruling in 2006, in a case where the FBI did just that, concluded that the process was legal.

5. Be careful when you throw out your old computer.

Did you remember to erase your whole disk before you tossed the old computer -- get rid of the password to your bank account, all the old taxes and a bunch of other things you had wanted to delete? Unless you really knew what you were doing, the information is still there, easily recovered. Even formatting the disk doesn't really erase anything. You have to use a special piece of software. There are plenty available. Or -- if you were really concerned and aren't giving the computer to someone who needs the drive -- take it out and whack it with a hammer. If you use your cell phone to read e-mail, same story -- deleting e-mail doesn't really get rid of it, so be careful who gets your old phone.